Fuse plug



Aug. 10 1926. 1,595,852

N.- c. BUTLER FUSE PLUG Filed Oct. 8, 1920 Patented Aug. 10, 1926.

UNITED STATES NATHAN C. BUTLER, OF CLEVELAND, OHIO.

FUSE PLUG.

Application filed October 8, 1920. Serial No. 415,629.

This invention relates to improvements in fuse plugs for use in electricinstallations.

The object of this invention is to provide a fuse plug comprising a mainmember having an exterior threaded contact for engagement in a suitablesocket and a removable member carrying the fuse which has its endssecured to a center contact and to a peripheral contact, respectively,the last named contact being removably connected to the main contactmember.

It is also the purpose of this invention to provide a removable memberwith an insulator extension between the two contacts for preventingarcing, to connect the fuse element to the peripheral contact'in asimple and efficient manner, and to further engage the removable memberin such a manner that it will hold the mica or other transarent windowin place in the main memer. Other objects of the invention are theprovision of suitable gas vents, the provision of suitable grooves forholding the fuse wire in place, the provision of simple andeflicientcontact means between the main member and the fuse carrying member, andalso to provide a simple and efficient means for anchoring the fusewire.

Other objects of this invention will be apparent from the followingdescription and claims when considered together with the accompanyingdrawing.

Fig. 1 is a side elevation of the fuse lug assembled; Fig. 2 is a sideelevation of the fuse plu assembled with part of the main member brokenaway; Fig. 3 is a vertical section of the main member; Fig. 4 is aninverted plan view of the main member; Fig. 5 is a vertical sectionthrough the fuse carrying member; Fig. 6 is an inverted plan view of thefuse carrying member with part of the exterior contact broken away; andFig. 7 is a top plan view of the fuse carrying member with art brokenaway.

The main mem er comprises the hollow tubular insulator portion 1 and thesocket engaging member 2 which is formed of electroconducting material.The socket en gaging portion 2 is secured to the insulator 1 by means ofthe struck-in portions 3 which securely engage the recesses 4 in theinsulator 1. The tangs 5 are struck out of the member 2 andextendinwardly so as to engage the lower end of the insulator. Thepurpose of these tangs is to provide a means of electric contact betweenthe fuse carrying member and the socket engaging mem- 1 nel 6 betweenthe socket engaging member and the lower end portion of the insulator 1.Then by the provision of the notches 7 in the lower end of the insulator1 communication is afforded between the chamber within the fuse plug andthe outside atmosphere. The avenue of communication between the chamberjust referred to and the outside atmosphere is by way of the notches 7which in fact amount to apertures or ports when the fuse carrying memberis in full engagement with the socket engaging member, thence throughthe annular channel or duct 6 and thence through the openings 8 formedby striking out the tangs 5. The upper portion of the insulator 1 isformed with an interior shoulder for the seating of the transparent disk9, such as glass, mica or the like, which is held in seated position bythe contact of the upper end of the fuse-carrying member when in fullengagement with the socket engaging member, as viewed in Fig. 2. Thelower ortion of the socket engaging member 2 1s screw threaded asindicated at 10 to re 'ceive the thread 11 on the fuse carrying upperendof this member is formed with a groove 16 for the reception of the fusewire 17 which further extends through the groove 18 formed in theintermediate portion'13. This end of the fuse 17 is anchored beneath thesplit ring 19 which firmly engages the intermediate portion 13 of theinsulator and seats upon the base portion 12. Bin 19 is ofelectrooonductive material and forms contact with tangs 5 upon fullengagement of the fuse member with the main member. The other end of thefuse 17 is anchored by means of electric contact member 20 which has aform somewhat similar to that of a bifurcated rivet. The head of thecontact 20 seats in the circular depression 21 in the insulator baseportion 12 and firmly clamps therein the end of the fuse wire 17. Theprongs 22 of the contact 20 have their upper ends, as viewed in Fig. 5,bulged outwardly as indicated at so as to firmly engage the inner wallof the tubular insulator when the contact 20 is inserted therein. Theprongs Q2 separately join the head portion of the contact 20 and havesullicient resilience for ready insertion and proper engagement in theinsulator. Instead of employing a single fuse wire, a plurality of wiresmay be employed and suitable grooves provided in the upper end and inthe intermediate portion 13 of the insulator member for the reception ofsuch wires as may be desired.

It will be seen from the foregoing that the removable fuse carryingmember comprises an insulator body portion, a center contact member andan annular contact member, together with a fuse which is electricallyconnected to the contact members; and that this fuse carrying member canbe assembled and removably secured in the socket engaging member;furthermore, when these parts are so assembled the upper end of the fusecarrying member will hold the glass or mica disk in proper seating position without interference by the fuse itself which lies in the groove16.

It will also be seen that gases formed within the fuse plug arepermitted to escape to the outside atmosphere. Furthermore, the tangs 5constitute a simple and efiicient means for the provision of a gas vent.and at the same time serve as contacts for engagement with the splitring 19 when the parts are fully assembled. The engagement of tangs :3with the insulator member 1 serves also as an additional means ofsecuring the member 2 against displacement toward the other end ofmember 1. The particular means for an horing the ends of fuse wirepermit ready renewal of such wire while the grooves through which thefuse extends serve to prevent displacement of the same. Altogether thisinvention constitutes a simple, economical and yet an extremelyefficient fuse plug.

Other advantages flowing from this invention will be apparent to thosefamiliar with the art to which it relates.

hat I claim is:

1. In a fuse plug, a main member comprising an insulator and a socketengaging member secured thereto, inwardly extending tangs struck out ofsaid socket engaging member, a fuse member removably secured within saidsocket engaging member and having a contact member for engagen'ient withsaid tangs, a second contact member carried by said fuse member, and afuse element extending between said last named contacts.

2. In a fuse plug, a main member comprising an insulator and a socketengaging member having apertures therethrough, the inner end of saidinsulator being formed with achannel having communication with saidapertures and with the interior of said insulator member, a fuse memberremovably secured in said socket engaging meniber and having electricconnection therewith.

3. In a fuse plug, a main member comprising an insulator, a socketengaging member secured to said insulator and having inwardly extendingtangs struck out thereof at the inner end of said insulator andproviding apertures, the inner end of said insulator being formed with achannel having communication with said apertures and with the interiorof said insulator, said tangs engaging the inner end of said insulator,a fuse member removably secured to said socket engaging men'iber andhaving electric connection therewith.

4. In a fuse plug, a main member comprising an insulator and a socketengaging member secured thereto and having inwardly extending tangsstruck out thereof and providing apertures therethrough, the inner endof said insulator being formed with an annular channel havingcommunication with said apertures and with the in' terior of saidinsulator, a fuse member renu "ably secured to said socket engagingmember and being provided with a con tact portion for engagement withsaid tangs, and electric connections therethrough.

5. In a fuse plug, a main member comprising an insulator and av socketengaging member, said socket engaging member being provided withinwardly extending contacts intermediate the ends thereof, a fuse memberremovably secured within and to said socket engaging member, a contactring carried by said fuse member and being adapted for electric contactwith the contacts upon said socket engaging member, a second contactcarried by said fuse member and a fuse wire extending between thecontacts upon said fuse member.

In testimony whereof I hereby affix my signature.

NATHAN C. BUTLER.

